1. Field of Invention
This invention relates generally to sterilization processes for the elimination of microbes, specifically, the invention is directed to a sterilization method utilizing a magnetohydrodynamic, (MHD) cell and apparatus for destroying the microbes.
2. Description of Prior Art
The importance of sterilization processing is well known to both the general public and to those skilled in the art. Sterilization processes are required to obtain substantially 100% microbe elimination while not altering the material that is being sterilized. In addition, sterilization of waste streams is becoming of greater importance for environmental reasons. Typical materials that require sterilization are food products, pharmaceuticals, cosmetics and medical waste. Medical waste sterilization is becoming increasingly important with higher population densities and the new contagious diseases.
A wide variety of sterilization processes exist using a variety of temperature, electrical and/or chemical processes. All of these processes have certain draw backs. Sterilization processes that use an elevated temperature have the disadvantages of the energy requirements of heating the material to a temperature adequate to kill microbes and the effect that it has on the material being sterilized. Typical negative side-effects of thermal processes on foods are protein denaturation and degradation of vitamins.
Electrical sterilization has been tried and has even been patented. U.S. Pat. No. 1,863,222, issued Jun. 14, 1932 proposes a method of sterilization food with high frequency electrical oscillations. A vacuum tube oscillator is proposed for generating a high frequency electric field. Material to be treated is placed within a receptacle disposed across the electrodes. The recommended frequency of operation is between 60 and 600 MHz.
An electrical process called Electro-Pure Process was popular in the 1930's but the process fell out of favor by 1960. The reason for the discontinuance of the process could not be found. However many papers indicate that electrical sterilization has had the problem of an inadequate kill rate of microbes. In addition, the process has the disadvantage of not being sporocidal.
U.S. Pat. No. 4,524,079 issued Jun. 18, 1985, proposes a sterilization of food products having relatively high electric resistivity by subjecting them to the pulses of an oscillating magnetic field. Material to be sterilized is subjected to an intensity of approximately 2-100 Tesla at a frequency of about 5-500 KHz. The inventor claims to decrease the microorganism population by approximately two orders of magnitude through the application of a single pulse. This process also has the disadvantage of not being sporocidal.